A 220 V input is supplied to a transformer. The output circuit draws a current of 2.0 A at 440 V. If the ratio of output to input power is 0.8, then the current drawn by primary winding is

Step-by-step solution

Given, input voltage supplied to transformer, V 1 = 220 V Current at output circuit of transformer, i 2 = 220 V V 2 = 440 V o u t p u t p o w e r P 2 I n p u t P o w e r P 1 = 0.8 ⇒ V 2 i 2 V 1 i 1 = 0.8 440 × 2 220 × i 1 = 0.8 ⇒ i 1 = 4 0.8 = 5 A Hence, current drawn by the primary windings is 5 A.